XWiki Platform Mentions UI vulnerable to Cross-site Scripting

Impact

It's possible to store Javascript or groovy scripts in an mention macro anchor or reference field. The stored code is executed by anyone visiting the page with the mention.

For example, the example below will create a file at /tmp/exploit.txt:

{{mention reference="XWiki.Translation" anchor="{{/html~}~}{{async async=~"true~" cached=~"false~" context=~"doc.reference~"~}~}{{groovy~}~}new File(~"/tmp/exploit.txt~").withWriter { out -> out.println(~"owned!~"); }{{/groovy~}~}{{/async~}~}"/}}

Patches

This issue has been patched on XWiki 14.4 and 13.10.6.

Workarounds

It's possible to fix the vulnerability by updating XWiki.Mentions.MentionsMacro and edit the Macro code field of the XWiki.WikiMacroClass XObject.

<a id="$anchor" class="$stringtool.join($cssClasses, ' ')" data-reference="$services.model.serialize($reference.reference, 'default')" href="$link">$content</a>

Must be replaced by

<a id="$escapetool.xml($anchor)" class="$stringtool.join($cssClasses, ' ')" data-reference="$escapetool.xml($services.model.serialize($reference.reference, 'default'))" href="$escapetool.xml($link)">
  $escapetool.xml($content)
</a>

See the patches:

• 14.4: https://github.com/xwiki/xwiki-platform/commit/4f290d87a8355e967378a1ed6aee23a06ba162eb
• 13.10.6: https://github.com/xwiki/xwiki-platform/commit/4032dc896857597efd169966dc9e2752a9fdd459#diff-4fe22885f772e47d3561a05348f73921669ec12d4413b220383b73c7ae484bc4R608-R610

References

• https://jira.xwiki.org/browse/XWIKI-19752

For more information

If you have any questions or comments about this advisory:

• Open an issue in Jira XWiki.org
• Email us at Security Mailing List